1. Field of the Invention
The present invention relates to a recycling method for a heat exchanger incorporated in an air conditioner or the like. The present invention also relates to a crushing apparatus used for a heat exchanger to separate a metal pipe, through which a refrigerant passes, and a radiating metal fin surrounding the metal pipe.
2. Description of Related Art
A heat exchanger built in an air conditioner or the like is composed mainly of pipes made of high-purity copper and a heat radiating assembly which employs aluminum radiating metal fins. The copper pipes are inserted in the heat radiating assembly, then the inside diameters of the copper pipes are spread by metal fittings, or a gas or the like so as to connect them together by contact bonding.
Such heat exchangers have been disposed of as industrial wastes because it has been difficult to draw out the copper pipes from the heat radiating assemblies when recycling the heat exchangers and because the copper pipes and the heat radiating assemblies together would hardly find themselves usable in the alloy applications.
There has been known a method disclosed in Japanese Unexamined Patent Publication No. 8-11022, wherein the outer periphery or peripheries of a single or a plurality of metal pipes, which have penetrated in a plurality of radiating metal fins at predetermined intervals in a heat exchanger, are expanded in a predetermined direction.
As more air conditioners or the like are consumed, however, the quantity of dumped heat exchangers has accordingly been increasing, and there have been social demands for establishing a method for recycling the heat exchangers.
Using impact crushers employed for general recycling processes as the crushing apparatuses for scrapping heat exchangers has been posing the problem set forth below.
The impact crushers inevitably apply external mechanical forces to heat exchangers when they crush them by using high impact. This tends to easily produce metallic powder at the time of impacting, and the metallic powder sticks to impact marks and it cannot be removed easily, with a consequent danger of the contamination by impurities; hence, the impact crushers have not been suitably used as the crushing apparatuses for heat exchangers from which high purity copper need to be recovered.
Regular shredding machines could be used because they are capable of performing consecutive processing. The regular shredding machines, however, are not able to prevent the contamination by impurities and they smash both copper pipes and radiating metal fins into very small pieces, making it difficult to separate these two different materials afterwards, resulting in low quality of recovered materials.